Cross-correlation map of the total (dt) and perpendicular (left, ∂T) and total and parallel (right, ∂R) gradients for different r, ranging from zero to 60 in both perpendicular (r_⊥) and parallel (r_∥) directions. The unit distance corresponds to 500 km in the solar wind plasma frame. The title indicates the noise map used. The overplotted straight white lines of different slopes indicate different angles of attack.